The present invention provides a composition for the topical administration of pharmaceutical active ingredients.
Various aerosol and non-aerosol quick breaking and slow breaking foams for the topical delivery of pharmaceutical active ingredients are known in the prior art. For example, the foam composition can be an aqueous emulsion system, which upon actuation, produces a stabilized, homogeneous, expandable foam which breaks easily with shear. A composition of this type is often referred to as an aerosol foam or “mousse”. Alternatively, the foam composition can be a slow-breaking foam, which collapses only upon more vigorous rubbing.
It is known to use mousse compositions to topically deliver pharmaceutical active ingredients. An example of such a composition is in Australian patent application 80257/87 which discloses a mousse composition for the topical delivery of the pharmaceutically active ingredient, minoxidil. However the efficiency of such systems to deliver pharmaceutically active ingredients is limited.
Moreover, the majority of topical lotions and creams known or suggested in the prior art for delivering pharmaceutically active ingredients contain large amounts of petrolatum or some other occlusive agent to act as a barrier over the skin. This barrier reduces the evaporation of moisture from the skin which leads to increased moisture in the stratum corneum and in the epidermis and enhances the topical delivery of the pharmaceutical active ingredients.
However, in practice it would not be desirable to include such large amounts of an occlusive agent in a mousse formulation because when dispensed the mousse formulation would be a less stable foam, and upon application, the occlusive agent would leave a greasy, sticky lather on the skin which would not be considered acceptable to the consumer.
In U.S. Pat. Nos. 5,002,680 and 4,981,677, there is disclosed mousse compositions that contain an occlusive agent such as petrolatum. These compositions are directed towards cosmetic purposes, and provide no disclosure on their suitability or otherwise to enhance the topical delivery of pharmaceutical active ingredients. Further, in respect of U.S. Pat. No. 4,981,677 the formulation includes a starch component. It is accordingly not apparent that an occlusive layer would be formed.
Accordingly, it would be a significant advance in the art if a mousse composition could be provided that enhanced the topical delivery of the pharmaceutical active ingredient while preferably still providing a pharmaceutically elegant and consumer acceptable composition.